This planning grant of molecular epidemiology presents a multidisciplinary approach to an important aspect of molecular epidemiology: gene-environment interaction. Crosstalk among the multidisciplinary team and collaborations to integrate novel technologies and/or methodologies into epidemiologic research are planned. The investigators will explore air pollution-related genetic susceptibility and instability for future population studies of gene-environment interactions on the risk of airborne pollutant-related diseases such as asthma, chronic obstructive pulmonary disease (COPD), and airway cancers. They will develop microarray gene chips to measure the genetic susceptibility (genotypes) and instability as measured by gene expression, and explore new statistical methodology to deal with exposure, genetic susceptibility, gene expression and related illnesses. The specific aims of the project are: Aim 1. To establish a multidisciplinary team and to increase crosstalk in order to foster collaborations to integrate novel technologies and methodologies into molecular epidemiology; and Aim 2. To conduct 3 pilot studies to identify allelic variants (polymorphisms) of environmental disease susceptibility genes; to examine air pollution-related global gene expressions; and to explore the related statistical methodology to analyze data with exposures, genotypes and gene expression matrix in order to foster future population-based molecular epidemiological studies of gene-environment interaction in determining the risk of environmentallyinduced diseases. The planned University of California at Los Angeles (UCLA) Molecular Epidemiology Project in Environmental Genome Projects builds upon existing resources and researches of the Southern California Particle Center and Supersite (SCPCS) and the UCLA Center for Occupational and Environmental Health (COEH). It takes advantage of the wide range of expertise and skill in epidemiology, molecular biology, environmental health sciences, toxicology, occupational medicine, and biostatistics/bioinformatics. The planning grant will address critical research questions in a broad-based effort to understand the mechanism of air pollution and its related susceptibility genotypes and gene expressions, to explore gene-environmental interactions, and to develop more effective methods for the identification of high risk individuals for prevention of air pollution-related diseases.